While heat, such as that evolved by a high-economy, performance-optimized diesel engine, for example, can be very low on the cylinder crankshaft housing, this characteristic does not apply to “hot zones” such as in manifolds, turbochargers, catalytic converters, etc. As a result of the increasingly compact design of engines, components which are not thermally “compatible” are coming to be in ever closer proximity. Hence it is necessary to use shielding components such as heat shields to protect adjacent heat-sensitive assemblies, such as sensors, fuel lines, pressure cells, body parts, and so forth. The situation is also exacerbated by the compact structure in that the high packing density of the assemblies constricts the cooling air flow in the engine compartment. Noise abatement measures can also contribute to this problem. For example, under certain circumstances plastic floor plates having the function of reducing the level of sound emerging from the engine compartment to the roadway can produce effective insulation whereby heat is trapped in the engine compartment. Because of their high surface temperatures in some phases, catalytic converters are among the heat sources which may necessitate the use of protective shield barriers. A typical example is that of design measures of positioning the catalytic converter in the immediate vicinity of the manifold. This design principle, which performs the function of rapid heat-up of the catalytic converter, and thus of reducing emissions in the cold start phase, shifts a major source of heat into the engine compartment where a considerable number of assemblies are crowded in a tight space. Another reason for the growing importance of shielding components such as heat shields is the trend toward use of thermoplastics. Light and economical materials with their exceptional moldability are rapidly becoming common in the engine compartment, but require special attention with respect to ambient temperatures generated at the application site in connection with other heat-generating engine parts (New materials and Development Tools for Protection from Heat, in MTZ December 2001, Vol. 72, pp. 1044 et seq.).
Structural components such as shielding components in the installed state frequently form arched bodies which surround the components to be shielded in the form of a shell or pipe. In the shielding of catalytic converters, a respective heat shield can have a more or less closed tubular shape, so that shielding encompassing the heat source is formed. During installation, the component sections are moved into the required three-dimensional position in which they form the desired arched or partially closed shielding by the component sections being suitably bent along the action line.
Structural components such as shielding components of the prior art call for a deformation of the metallic material of the structural component forming a bending bead as the action line designed to enable a predetermined change of position of the component sections adjacent to the action line. As has been shown, problems however arise when the known structural components are installed. If the component sections are bent on the bending bead with a comparatively large bending angle, there is the danger of buckling of the material or lack of stiffness of the bending area as a result of overly great material stress. Increased resiliency behavior after completed bending also appears. In structural components intended for repeated installation, there is the danger that stability of shape is not ensured upon repeated installation.